Bipolar electrolytic cell for the production of gases



June 6, 1967 M-. s. KIRCHER 3,

BIPOLAR ELECTROLYTIC CELL FOR THE PRODUCTION OF GASES Filed Jan. 9, 1963 3 Sheets-Sheet 1 June 6, 1967 M. s. KIRCHER BIPOLAR ELECTROLYTIC CELL FOR THE PRODUCTION OF GASES 3 Sheets-Sheet 5 Filed Jan. 9, 1963 United States Patent Ofiice 3,324,023 BIPOLAR ELECTROLYTIC CELL FOR THE PRO- DUCTION F GASES Morton S. Kircher, Dryden, Ontario, Canada, assignor to Hooker Chemical Corporation, Niagara Falls, N.Y., a

corporation of New York Filed Jan. 9, 1963, Ser. No. 250,331 11 Claims. (Cl. 204256) This invention relates to an improved electrolytic cell and more particularly relates to improvements in electrolytic cells for the electrolysis of hydrochloric acid to produce chlorine and hydrogen.

In recent years, numerous industrial processes have been developed involving the chlorination of organic compounds. Many of these processes result in the formation of by-product HCl gas. Generally, it is the practice to recover the HCl as an aqueous hydrochloric acid, containing about 32 percent HCl. As the production of chlorinated organic has increased, with the resulting increase in the production of by-product HCl, the problem of disposing of this latter material has, in many instances, become acute.

Processes which utilize HCl have not been developed fast enough to keep up with the supply. Moreover, it is generally not economical to ship it over long distances because of freight charges on a material that is about twothirds water. Additionally, because of anti-polution laws in many areas, it is not possible to dump the hydrochloric acid in waterways or release the HCl gas into the atmosphere. Accordingly, in recent years, consideration has been given to the development of processes for producing chlorine from this HCl.

Among the processes developed for this purpose are those which involve the electrolysis of hydrochloric acid or of a solution of a metal chloride, such as copper chloride or nickel chloride, which is formed using the hydrochloric acid. Of these, the former, i.e., the direct electrolysis of the acid, has shown the most commercial promise.

Heretofore, in carrying out the direct electrolysis of hydrochloric acid, the electrolytic cells used have been bipolar cells of the filter-press type. These cells or assemblies are formed of a plurality of elements or single cells, each of which consist of a frame of an acid-resistant material having a graphite plate secured thereto. Each of these graphite plates acts as a bi-polar electrode so that one side of the plate performs as an anode and the other side performs as a cathode. To the cathode side of the electrode plate, an acid-resistant diaphragm is secured so as to cover the cathodic face of the plate. A number of these elements, generally as many as forty, are then clamped together so as to form a series of cells having a free space left between the diaphragm of one cell and the opposite anodic face of the graphite plate of the next cell. Frequently, in these cells, this free space is filled with graphite particles. Although cell assemblies of this type have been found, generally, to be effective in electrolyzing hydrochloric acid to produce chlorine and hydrogen, the capital investment required to fabricate and assemble them is undesirably high. Additionally, because the assembly is formed of a plurality of separate cell units, leakage at the joints between these separate units is a problem. Moreover, in the event that repair of the assembly is required, it is necessary to disassemble the entire structure. This is both time-consuming and expensive. Up to the present time, however, no electrolytic cells have been developed for the electrolysis of hydrochloric acid which overcome the aforementioned difiiculties and which may also be fabricated more easily and economically.

It is, therefore, an object of the present invention to provide a novel electrolytic cell for the electrolysis of hy- 3,324,023 Patented June 6, 1967 drochloric acid, whrein the problems encountered in the prior art cells for this purposes are overcome.

Another object of the present invention is to provide a novel cell for the electrolysis of hydrochloric, acid, which cell is easily and economically fabricated.

Another object of the invention is to provide a novel method of fabricating a cell for the electrolysis of hydro chloric acid.

A further object of this invention is to provide a novel method of producing C1 and H by the electrolysis of hydrochloric acid.

These and other objects will become apparent to those skilled in the art from the description of the invention which follows.

In the drawing which is attached hereto and forms a part hereof, FIGURE 1 is a plan view of a portion of an electrolytic cell constituting one embodiment of the present invention; FIGURE 2 is a side section of the electrolytic cell shown in FIGURE 1; and FIGURE 3 is a schematic diagram showing the electrolyte recirculating system for an electrolytic cell embodying the present invention.

The electrolytic cell of the present invention includes an outer casing member of open box-like construction,

wherein are positioned, in spaced relationship, a plurality of bi-polar electrode members, each of which is separated from the next adjacent bi-polar electrode member by a fluid-permeable diaphragm. The electrode members and diphragms are positioned within the casing so as to provide an area between each electrode member and the diaphragm on either side through which an electrolyte can be passed in contact with substantially the entire face of the electrode member. The electrode members and dia phragms are secured to the casing member so as to be substantially immovable within the casing and, thus, maintain the spaced relationship between them. Means are provided for introducing electrical energy into the cell, whereby a current may be passed through the cell from one electrode to the next, so as to electrolyze the electrolyte in contact with the electrodes. Means are also provided for separately removing gaseous products from the cell and for introducing an electrolyte into the cell and circulating it therethrough. Additionally, ber is provided with a cover member which is secured thereto in substantially gas and fluid tight relation.

The outer casing member and cover of the subject electrolytic cell may be formed of any electrically nonconductive material which is resistant to chlorine and hydrochloric acid and which will withstand the temperatures at which the cell is operated. Generally, these temperatures are about ninety degrees centigrade. Exemplary of materials which may be used are high temperature polyvinyl chloride, hard rubber, chlorendic acid based polyester resins, and the like. It will be appreciated, that the materials of construction used for the casing member and cover preferably have sufficient rigidity as to be self-supporting. Alternatively, however, the casing and cover members may be formed of a material which does not fulfill all of the above mentioned criteria, such as concrete or cement which is not resistant to hydrochloric acid and chlorine, and have the interior of these members coated with a material which does fulfill these requirements. Additionally, even in the case of materials which are substantially self-supporting, such as rigid polyvinyl chloride, it may be desirable to provide reinforcing members around the exterior of the casing, such as metal bands, to provide additional rigidity.

The electrodes for the subject electrolytic cell may be formed of any electrically conductive material which will resist the attack of hydrochloric acid and chlorine. Most generally, the electrodes will be formed of carbon or graphite. Preferably, the electrodes will be in the form of the casing memgraphite plates although it will be appreciated that graphite blades, such as those used in chlor-alkali cells, may be cemented together to form an electrode plate for the present cell. In such instances, the cement used must, of course, be resistant to chlorine and hydrochloric acid. Instead of the carbon or graphite electrodes, metallic electrodes such as those made of platinized titanium, may be used equally well in the present cell. Generally, up to the present time, however, the cost of such metallic electrodes has made their use economically unattractive.

The diaphragms for the subject electrolytic cell may be made of any liquid permeable material which will prevent the passage of gas from one electrode compartment to the next and which will be resistant to the conditions under which the cell is operated. Exemplary of materials which may be used for the diaphragm are cloth made out of glass or suitable synthetic organic plastic, such as polyvinyl chloride, polyetetrafiuoroethylene (Teflon), and the like. Additionally, the diaphragm may be made out of asbestos, although this material generally is not the most preferred. This is based on the fact that the present cell does not have cathode screens, so a deposited asbestos diaphragm cannot be used and it is necessary to use asbestos paper, which material may be easily ruptured.

Referring now to the drawing, FIGURE 1 is a plan view of a portion of an electrolytic cell embodying the structure of the present invention. As is shown in this figure and in FIGURE 2, the electrolytic cell of the present invention includes an outer casing member having side Walls 1, end Walls 4, and a base 2. Within this casing member are disposed alternating electrodes and diaphragms. As is shown most clearly in FIGURE 2, an end electrode 6 is butted against the end wall 4 and the bottom 2 of the casing member and extends above the top of the casing member. To the top of this electrode 6, is secured the electrical lead 29 by means of which electrical energy is introduced into the cell. Another end electrode is similarly positioned at the opposite end of the cell, likewise butting against the other end wall and the bottom of the casing member. To this electrode is connected the electrical lead of opposite charge so as to complete the electrical circuit. This latter end electrode, being a substantial duplicate of the first end electrode, is not shown in the drawing.

Next to the end electrode 6, is disposed a diaphragm 5. This diaphragm is secured at each end by spacer members 7 which spacer members are secured to the side walls 1 of the outer casing member. These spacing members are formed of an electrically non-conductive material which is resistant to chlorine and to hydrochloric acid at the temperatures at which the cell is operated. Generally, it is preferred to form the spacer members of the same material as is used in fabricating the casing member. As is shown in FIGURE 1, the spacer members are journaled into the side walls 1 of the casing member. In this manner, the spacer members, as well as the diaphragm which they support, are substantially immovably mounted in the cell casing. The spacing members are positioned in the side walls of the casing member so that the face of the diaphragm supported by the spacing members is substantially parallel to the face of the end electrode 6. As is shown in FIGURE 2, the top and bottom edges of the diaphragm are secured to frame members 8, which frame members are secured to the base 2 and the cover 11 of the casing. As with the side spacers 7, the end frame members 8 may be journaled in the base member 2 of the casing and in the cover member 11. In this manner, added support is given to the diaphragm 5 and the maintenance of the parallel alignment between the diaphragm face and the face of the adjacent electrode is assured.

A bi-polar electrode member 3 is placed in the casing member, butting against the spacer members 7 of the diaphragm 5. The length of this electrode member is only slightly less than the inside width of the casing member as measured between the opposite side walls 1. Preferably, only a minimum amount of space is left between the ends of the electrode 3 and the side walls 1 of the casing members, although there should be sufiicient clearance so that the electrode may be easily inserted into the casing member. As is shown more clearly in FIGURE 2, spline members 9 are provided at the top and the bottom of the electrode 3 to secure it to the base 2 and the cover member 11 of the casing member. These spline members, in conjunction with the spacer members 7 on the diaphragm, secure the electrode 3 substantially immovably within the casing member and maintain a substantial parallel relationship between the face of the electrode 3 and the diaphragm 5.

It will be noted that the electrode 3 is a bi-polar electrode. Accordingly, as viewed in FIGURE 2, the left-hand face of the electrode 3 is the cathode and has a negative charge while the right-hand face of the electrode is the anode and has a positive charge. The spline members 9, therefore, serve a function in addition to that of securing the electrode within the casing member, which function is formation of separate anode and cathode compartments within the casing member. Additional diaphragms 5 and electrodes 3 are also inserted into the cell casing member in the manner heretofore set forth. As is shown in the drawings, these alternating diaphragms and electrodes, with their support and spacer members, form a series of individual electrolytic cells each having an anode surface, a diaphragm, and a cathode surface. The electrolyte, hydrochloric acid, is introduced into each of these cells, in both the anode compartment and the cathode compartment. The electrolyte in these compartments is brought into contact with substantially the entire face of the electrode in that compartment, which electrode face is either anodic or cathodic.

Separate means are provided for removing the anolyte and catholyte from the cell, which means are shown in FIGURES l as 13 and 17, respectively. As shown in FIGURE 1, the anolyte outlets 13 extend from the various anode compartments of the cell to a collector or manifold 21. Similarly, the catholyte outlets 17 extend from the cathode compartments to a second collecting member or manifold 22. As is shown in FIGURE 2, these anolyte and catholyte outlets are positioned in the upper portion of the casing member, above the top of the electrodes 3. It is to be noted that in both of the manifolds 21 and 22, barriers 23 are placed which maintain a separation between the various electrolyte streams removed from the cell. This barrier may terminate short of the bottom of the manifold so that, ultimately, mixing of all of the anolyte streams and of all of the catholyte streams is accomplished. By providing these barriers 23 in the manifolds 21 and 22, current leakage or short circuiting between the various anolyte streams and the various catholyte streams is minimized. Although, if the anolyte streams are combined and the catholyte streams are combined in the bottom of the manifolds, there will be some current leakage, the amount of such leakage at this point will not be so great as to present a serious problem.

Anolyte and catholyte inlets 15 and 19, respectively, are provided at the bottom of the anode and cathode compartments, near the base of the cell. These inlets are similar in structure to the anolyte and catholyte outlets, as described hereinabove. As is shown in FIGURE 3, the anolyte and catholyte inlets come from the manifolds 21 and 22, respectively, into the cell. Additionally, an inlet 25 is provided in the manifold 21 for introducing fresh hydrochloric acid into the manifold for distribution into the cell, and an outlet 27 is provided in the manifold 22 for removing depleted hydrochloric acid. It is preferred that in fabricating the present cell the anolyte and catholyte inlets are positioned somewhat above the base 2 of the casing. Inasmuch as during the operation of the cell there is some sludge formation, which sludge tends to settle to the bottom of the cell, by maintaining the anolyte and catholyte inlets above the base of the cell plugging of these inlets by this sludge is minimized.

The entire cell structure is provided with a cover member 11 which cover member provides a substantially gas and liquid tight seal at the top of the casing member. As is shown in FIGURE 2, the cover member is formed of a series of elongated members, preferably of the same material as the casing member, which elongated members are sealed to the diaphragm frame members 8 and electrode splines 9. Any suitable sealing material, which is resistant to chlorine, may be used for this purpose, as for example asphalt. Additionally, a seal is effected between the cover member 11 and the end and side walls of the casing member, using suitable gaskets or sealing material, such as asphalt.

It will be noted, as has been shown in the drawings, that the diaphragm spacer members 7 are shown as being journaled in the walls 1 of the casing member and that the ends of the electrodes 6 and 3 are shown as butting against the side wall. It will be appreciated, however, that other means of achieving the desired spaced relationship between the electrodes and the diaphragms may be used. Exemplary of such other methods arc welding or cementing the spacer members 7 to the side walls 1 of the casing. Alternatively, the side walls 1 of the casing member may be formed with appropriate slots into which the diaphragm and electrodes may be placed, thereby maintaining the desired spaced relationship between them. Similar fabrication techniques may also be used for securing the top and bottom of the electrodes and diaphragms to the base of the casing member and to the cover member of the cell.

In assembling the cell of the present invention, the side walls 1 and one end wall 4 are secured to the casing base 2 in any desired manner. Although the base member with two side walls and one end wall may be molded as a single piece, it is generally more economical to form the sections separately and then bolt them or weld them together. Where the latter source is followed, appropriate gasketing or sealing, as required, will be provided in the corners and at the base of the structure. Thereafter, the end electrode 6 is placed in the cell, in contact with the end wall 4 of the casing member.

After positioning the end electrodes 6 in the casing member, the first diaphragm 5 is positioned in the casing. This is done by securing a spacer member 7 on each of the side walls, in contact with the end electrode 6. A diaphragm frame member 8 is also cemented into the base 2 of the casing and the edges of the diaphragm are pressed into slots provided in the spacer 7 and the frame member 8. A thin rod of plastic material, resistant to the conditions Within the cell and which is electrically non-conductive, is then pressed into the slots in the spacer 7 and the bottom frame 8 so as to firmly hold the diaphragm 5 taut. A top frame member 8 is then similarly secured to the diaphragm. A graphite electrode is then inserted into the casing member so as to butt against the spacer members 7 of the diaphragm. A spline 9 is secured to the base of the cell and fits into a slot on the bottom of the electrode. A second spline member 9 is then inserted into a slot on the top of the electrode as well as into slots or grooves in the side walls 1 of the casing member. The assembly of the cell is completed by adding successive rows of diaphragms and graphite electrodes in the same manner as set forth hereinabove. Generally, the completed assembly will contain about forty electrodes. The last electrode inserted into the cell is an end electrode 6, which is in contact with the second end wall 4 of the casing member which is then bolted into position. The cover member 11 is then formed using separate strips of the electrically nonconductive casing material which strips are sealed to the upper diaphragm frame members 8 and the electrode splines 9 which extend up above the top of the side and end walls of the casing member.

In operation of the subject cell, an electrolyte, comprising a concentrated aqueous solution of hydrochloric acid, is introduced into the manifold 21 through the inlet 25 and flows through the anolyte inlets 15 into the anode compartment wherein it also percolates through the diaphragm into the cathode compartments. A positive elec-. trical lead is attached to one end electrode 6 of the cell and a negative lead to the other. As current is passed into the cell, electrolysis of the hydrochloric acid electrolyte takes place within each of the separate electrical cells, forming chlorine which is released at the anode and hydrogen which is released at the cathode. By introducing the electrolyte into the bottom of the anode and cathode compartments, advantage is taken of the gas lift of the rising chlorine and hydrogen gases as they are formed at the anodes and cathodes, respectively. -In this manner, the electrolyte is forced upwardly through the anode and cathode compartments into the respective anolyte and a catholyte outlets 13 and 17, respectively. The anolyte, comprising hydrochloric acid and chlorine gas, is removed from the anode compartments through the anolyte outlets 13 and passes into the manifold 21 wherein a gas space is provided at the top of the manifold for collection of the chlorine gas which is then removed from the manifold. The anolyte is then recirculated back into the cell through the anolyte inlets 15 to be introduced at the bottom of the anode comparments. Similarly, the catholyte containing hydrochloric acid and hydrogen is removed from the cathode compartments through the catholyte outlets 17 and passe-s into the manifold 22 wherein a similar separation of the hydrochloric acid and the hydrogen gas is effected. The catholyte is then reintroduced into the cell through the catholyte inlets 19 into the bottom of the cathode compartments. Depleted hydrochloric acid is removed from the manifold 22 through the outlet 27. It is to be noted that where the barrier members 23 in the manifolds 21 and 22 extend all the way to the bottom of the manifold, thereby forming completely separate compartments for the introduction of the electrolyte from the separate anode and cathode compartments,it may be advisable to provide separate electrolyte inlets 25 and outlets 27 for each of the separate compartments. A single inlet into an anode compartment near one end of the cell and a similar single outlet from one cathode compartment near the opposite end of the cell has been found to be sufficient in many instances, however.

It has been found that the electrolytic cell assembly of the present invention is considerably cheaper and easier to fabricate than the prior cells of the filter-press type, Additionally, maintenance of these cells is also greatly simplified over those of the filter-press type.

Although there have been described various embodiments of the invention, the structures and methods described are not intended to be understood as limiting the scope of the invention, as it is realized changes therewithin are possible, and it is further intended that each element recited in any of the following claims is to be understood as referring to all equivalent elements for accomplishing substantially the same results in substantially the same or equivalent manner, it being intended to cover the invention broadly in whatever form its principle may be utilized.

What is claimed is:

1. Apparatus for the electrolysis of an electrolyte to produce different gases which comprises an outer casing member, said member having substantially gas and fluid tight walls, a cover member for said casing member, said cover member being secured to the casing member in substantially gas and fluid tight relationship, a plurality of bi-polar electrode members positioned within the casing member in spaced relationship and secured to the casing member so as to be susbtantially immovable within the casing member, a plurality of fluid-permeable diaphragms positioned within the casing member and secured thereto so as to be substantially immovable within the casing member, the electrode members and diaphra-gms being positioned within the casing member so that each electrode member is separated from the next adjacent electrode member by a diaphragm, the electrode members and the diaphragm being spaced apart so as to form electrode compartments between the anodic surfaces of the bi-polar electrodes and the diaphragms and cathode compartments between the cathodic surfaces of the bi-polar electrodes and the diaphragms, through which compartments an electrolyte can be passed in contact with substantially the entire anodic and cathodic surfaces, respectively, of the electrodes, means for introducing an electrolyte into the anode and cathode compartments, means for introducing electrical energy into the apparatus so as to effect electrolysis of the electrolyte and form a gas in the anode compartment and a different gas in the cathode compartment, means for removing the catholyte and gas produced from the cathode compartment, and means for removing the anolyte and gas produced from the anode compartments, said means being separate for each of said compartments, electrical barrier means for maintaining electrical separation of the anolyte removed from each of said anolyte compartments and for maintaining electrical separation of the catholyte removed from each of said cathode compartments, means for separating the anolyte and the gas produced in the anode compartment, means for separating the catholyte and the gas produced in the cathode compartment, means for introducing fresh electrolyte into the apparatus and means for removing depleted electrolyte from the apparatus.

2. The apparatus as claimed in claim 1 wherein the bi-polar electrodes members and the diaphragms are disposed substantially vertically within the casing member.

3. Apparatus for the electrolysis of an electrolyte to produce different gases which comprises, an outer casing member, said member having substantially gas and fluid tight walls, a plurality of bi-polar electrode members positioned within the casing member in spaced relationship and secured to the casing member so as to be substantially immovable within the casing member, a plurality of fluid-permeable diaphragms positioned within the casing member and secured thereto so as to be substantially immovable within the casing member, the electrode members and the diaphragms being positioned within the casing members so that each electrode member is separated from the next adjacent electrode member by a diaphragm, the electrode members and the diaphragms being spaced apart so as to form anode compartments between the anodic surfaces of the bi-polar electrodes and the diaphragms and cathode compartments between the cathodic surfaces of the bi-polar electrodes and the diaphragms through which an electrolyte can be passed in contact with substantially the entire respective, anodic and cathodic surfaces of the electrodes, means for introducing an electrolyte into the anode and cathode compartments, said means being positioned so as to introduce the electrolyte into the bottom of the compartments and effect upward circulation of the electrolyte through the compartments, means for introducing electrical energy into the apparatus so as to effect electrolysis of v the electrolyte and form a gas in the anode compartment and a different gas in the cathode compartment, means for removing the catholyte and gas produced from the cathode compartments and means for removing the anolyte and gas produced from the anode compartments, said means being separate for each of said compartments, electrical barrier means for maintaining electrical separation of the anolyte removed from each of said anolyte compartments and for maintaining electrical separation of the catholyte removed from each of said cathode compartments, means for separating the gas produced in the anode compartment from the anolyte, means for separating the gas produced in the cathode compartment from the catholyte, means for recirculating the anolyte from which the gas is removed back into the bottom of the anode compartments, means for recirculating the catholyte from which the gas has been removed back into the hottom of the cathode compartments, means for introducing fresh electrolyte into the apparatus, means for removing depleted electrolyte from the apparatus, and a cover member for the casing member, the cover member being secured to the casing member in a substantially gas and fluid tight relationship.

4. The apparatus as claimed in claim 3 wherein the bi-polar electrode members and diaphragms are disposed substantially vertically within the casing member.

5. An electrolytic cell assembly for the electrolysis of hydrochloric acid to produce hydrogen and chlorine which comprises an outer casing member of open box-like construction having a base, end walls and side walls secured together in substantially gas and fluid tight relationship, a cover member for said casing member secured thereto in substantially gas and fluid tight relationship, a plurality of separate electrolytic cells disposed within said casing member, each of said cells comprising an anode, an anode compartment, a fluid-permeable diaphragm, a cathode compartment, and a cathode, the separate electrolytic cells being formed by alternately disposed bi-polar electrode members and fluid-permeable diaphragms, said electrode members and diaphragms being secured to the casing member so as to be substantially immovable therein and form an anode compartment between the anodic surface of one electrode and the next adjacent diaphragm and a cathode compartment between this diaphragm and the cathodic surface of the next adjacent electrode, means for introducing an electrolyte into the anode and cathode compartments, means for introducing electrical energy into the cell assembly so as to electrolyze the electrolyte within these compartments and form chlorine in the anode compartments and hydrogen in the cathode compartments, means for removing the anolyte and chlorine from the anode compartments, means for removing the catholyte and hydrogen from the cathode compartments, said means being separate for each of said compartments, electrical barrier means for maintaining electrical separation of the anolyte removed from each of the anolyte compartments and for maintaining electrical separation of the catholyte removed from each of the catholyte compartments, means for separating chlorine from the anolyte, means for separating hydrogen from the catholyte, means for reintroducing the anolyte from which the chlorine has been separated into the anode compartments, means for reintroducing the catholyte from which the hydrogen has been separated into the cathode compartments, means for introducing fresh hydrochloric acid into the anolyte before it is returned to the anode compartments, and means for removing depleted hydrochloric acid from the catholyte before it is returned to the cathode compartments.

6. The apparatus as claimed in claim 5 wherein the bipolar electrode members and the diaphragms are disposed substantially vertically within the casing member.

7. Apparatus for the electrolysis of hydrochloric acid to produce chlorine and hydrogen which comprises a substantially gas and fluid tight outer casing member of open box-like construction, having a base, two oppositely disposed end walls and two oppositely disposed side walls, a cover member for said casing member, said cover member being secured to the casing member in substantially gas tight relationship, the interior surface of the side walls of the casing member being formed into substantially parallel vertically disposed alternating depressions and ridges, the depressions and ridges in one side Wall being substantially oppositely dispose-d to corresponding depressions and ridges in the opposite wall, a plurality of bi-polar electrode members positioned within the casing member and extending between the casing side walls, the ends of said electrode members being disposed within the depressions formed in the side walls, a plurality of fluid-permeable diaphragms similarly positioned within the casing member and disposed between the electrode members, the ends of said diaphragms being secured to the ridges formed on the casing side walls, the electrode members and diaphragms being so positioned within the casing member as to form an anode compartment between the anodic surface of one 'bi-polar electrode and the next adjacent diaphragm and a cathode compartment between this diaphragm and the cathodic surface of the next adjacent bi-polar electrode, a plurality of electrolyte inlets for introducing hydrochloric acid into the anode and cathode compartments, one of said inlets being disposed in each compartment and positioned in the bottom portion of the compartment so as to effect upward circulation of the hydrochloric acid through the compartment, electrical leads secured to the end electrodes adjacent to the end walls of the casing member, whereby electrical energy introduced into one end electrode is passed through the apparatus to the opposite end electrode and electrolysis of electrolyte is effected with the formation of chlorine in the anode compartments and the formation of hydrogen in the cathode compartments, a plurality of outlets, one of which is disposed in each of the anode and cathode compartments, said outlets being positioned in the upper portion of the compartments so as to remove the anolyte and chlorine from the anode compartments and the catholyte and hydrogen from the cathode compartments, electrical barrier means in each of said outlets for maintaining electrical separation of the anolyte removed from the anode compartment while combining the chlorine removed from all of the anode compartments and for maintaining electrical separation of the catholyte removed from the cathode compartments while combining the hydrogen removed from all of the cathode compartments, means for recirculating the anolyte from which the chlorine has been removed back into the anode compartments, means for recirculating the catholyte from which the hydrogen has been removed back into the cathode compartments, means for introducing fresh hydrochloric acid into the anolyte before it is recirculated back to the cathode compartments, and means for removing depleted hydrochloric acid from the catholyte 10 before it is recirculated back into the cathode compartments.

8. The apparatus as claimed in claim 7 wherein there are provided means for securing the bottom edges of the electrodes and the diaphragms to the base of the casing member and means for securing the top edges of the electrode members and diaphragms to the cover member.

9. The apparatus as claimed in claim 7 wherein the fresh hydrochloric acid electrolyte is added only to the anolyte from the anode compartment adjacent to the end wall of the casing member and the depleted hydrochloric acid electrolyte is removed only from the catholyte from the cathode compartment adjacent the opposite end wall of the casing member.

10. The apparatus of claim 1 wherein the electrodes are graphite.

11. The apparatus of claim 1 wherein the electrodes are platinized titanium.

References Cited UNITED STATES PATENTS JOHN H. MACK, Primary Examiner. MURRAY TILLMAN, Examiner.

L. G. WISE, D. R. JORDAN, Assistant Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,324,023 June 6, 1967 Morton S. Kircher It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below Column 2, line 1, for "whrein" read wherein line 2, for purposes" read purpose line 4, for "hydrochloric," read hydrochloric line 28, for "diphragms" read diaphragms column 6, line 26, for "'comp'arments" read compartments line 71, for "susbtantially" read substantially column 7, line 31,

for "electrodes" read electrode Signed and sealed this 17th day of December 1968.

(SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer 

1. APPARATUS FOR THE ELCTROLYSIS OF AN ELECTROLYTE TO PRODUCE DIFFERENT GASES WHICH COMPRISES AN OUTER CASING MEMBER, SAID MEMBER HAVING SUBSTANTIALLY GAS AND FLUID TIGHT WALLS, A COVER MEMBER FOR SAID CASING MEMBER, SAID COVER MEMBER BEING SECURED TO THE CASING MEMBER IN SUBSTANTIALLY GAS AND FLUID TIGHT RELATIONSHIP, A PLURALITY OF B-POLAR ELECTRODE MEMBERS POSITIONED WITHIN THE CASING MEMBER IN SPACED RELATIONSHIP AND SECURED TO THE CASING MEMBER SO AS TO BE SUBSTANTIALLY IMMOVABLE WITHIN THE CASING MEMBER, A PLURALITY OF FLUID-PERMEABLE DIAPHRAMS POSITIONED WITHINT THE CASING MEMBER AND SECURED THERETO SO AS TO BE SUBSTANTIALLY IMMOVABLE WITHIN THE CASING MEMBER, THE ELECTRODE MEMBERS AND DIAPHRAMS BEING POSITIONED WITHIN THE CASING MEMBER SO THAT EACH ELECTRODE MEMBER IS SEPARATED FROM THE NEXT ADJACENT ELECTRODE MEMBER BY A DIAPHRAGM, THE ELECTRODE MEMBERS AND THE DIAPHRAM BEING SPACED APART SO A TO FORM ELECTRODE COMPARTMENTS BETWEEN THE ANODIC SURFACES OF THE BI-POLAR ELECTRODES AND THE DIAPHRAMS AND CATHODE COMPARTMENTS BETWEEN THE CATHODE SURFACES OF THE BI-POLAR ELECTRODES AND THE DIAPHRAGMS, THROUGH WHICH COMPARTMENTS AN ELECTROLYTE CAN BE PASSED IN CONTACT WITH SUBSTNATIALLY THE ENTIRE ANODIC AND CATHODIC SURFACES, RESPECTIVELY, OF THE ELECTRODES, MEANS FOR INTRODUCING AN ELECTROLYTE INTO THE ANODE AND CATHODE COMPARTMENTS, MEANS FOR INTRODUCING ELECTRICAL ENERGY INTO THE APPARATUS SO AS TO EFECT ELECTROLYSIS OF THE ELECTROLYTE AND FORM A GAS IN THE ANODE COMPARTMENT AND A DIFFERENT GAS IN THE CATHODE COMPARTMENT, MEANS FOR REMOVING THE CATHOLYTE AND GAS PRODUCED FROM THE CATHODE COMPARTMENT, AND MENAS FOR REMOVING THE ANOLYTE AND GAS PRODUCED FROM THE ANODE COMPARTMENTS, SAID MENAS BEING SEPARATE FOR EACH OF SAID COMPARTMENTS, ELECTRICAL BARRIER MEANS FOR MAINTAINING ELECTRICAL SEPARATION OF THE ANOLYTE REMOVED FROM EACH OF SAID ANOYTE COMPARTMENTS AND FOR MAINTAINING ELECTRICAL SEPARATION OF THE CATHOLYTE REMOVED FROM EACH OF SAID CATHODE COMPARTMENTS, MEANS FOR SEPARATING THE ANOLYTE AND THE GAS PRODUCED IN THE ANODE COMPARTMENT, MEANS FOR SEPARATING THE CATHOLYTE AND THE GAS PRODUCED IN THE CATHODE COMPARTMENT, MEANS FOR INTRODUCING FRESH ELECTROLYTE INTO THE APPARATUS AND MEANS FOR REMOVING DEPLETED ELECTROLYTE FROM THE APPARATUS. 